Pet blow moulding machines

Abstract

A blow molding machine for blow molding a container having an integrally formed handle; said container blow molded from a previously injection molded preform; said preform comprising a body portion and said integrally formed handle; said machine including a preform loading station at which said preform is oriented by a preform orienting apparatus.

The invention claimed is: 
     
       1. A method for controlling a preform for stretch blow molding a container with an integrally formed handle, said preform comprising a body portion and said integrally formed handle, said preform transferred from a preform supply source to a blow molding tool for blowing said container, said method including the steps of:
 a. passing said preform through a preform handle orienting apparatus; 
 b. transferring said preform to a preform transportation system; 
 c. transferring said preform from said transportation system to said blow molding tool; 
 d. maintaining orientation of said preform handle imposed by said handle orienting apparatus during said transfer to said preform transportation system and said transfer to said blow molding tool; 
 e. setting heat outputs of individual preform heating elements to deliver a required distribution of heat density to said body portion of said preform, 
 f. rotating said preform during transport along said transportation system past an array of the preform heating elements; and 
 g. shielding said integrally formed handle from excessive exposure to heating from said heating elements. 
 
     
     
       2. A method as claimed in  claim 1  for preheating a preform, said preform comprising a body portion and an integrally attached handle, said method including the steps of:
 a. orienting said preform so as to engage said preform with a transport system mandrel, said mandrel provided with a shield substantially covering said handle; 
 b. arranging banks of the heating elements into a pattern allowing for rotation of said handle and said shield; 
 c. rotating said preform during a preheating stage as said transport system carries said preform past said banks of heating elements.